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Biomedical subjects

B A Keagy

Publications and source records attributed to B A Keagy.

At least 37 records · Page 2Linked to original sources
PubMed1996

One hundred consecutive thymectomies for myasthenia gravis.

BACKGROUND: Between June 1997 and November 1993, 100 consecutive thymectomies for myasthenia gravis were performed at University of North Carolina Hospitals in Chapel Hill. METHODS: A consistent, planned protocol involving preoperative, intraoperative, and postoperative care was followed. All thymectomies were performed through a median sternotomy with removal of all visible thymus and perithymic fat in the anterior mediastinum. RESULTS: There was no perioperative mortality or longterm morbidity. Mean postoperative hospital stay was 6.3 days (range, 3 to 18 days). Ninety-six percent of the patients were extubated the day of the operation, and all patients were extubated within 24 hours. Mean postoperative intensive care unit stay was 1.2 days (range, 1 to 4 days). After a mean follow-up of 65 months (range, 1 to 199 months), 78% of all patients are improved by at least one modified Osserman classification when their current status is compared with their worst preoperative disease severity. In fact, 69% of patients with mild disease preoperatively (class I, II, or III maximal severity) are in pharmacologic remission (asymptomatic without regular medication), whereas 29% of patients with severe disease (class IV or V) are in remission (p = 0.0001). CONCLUSIONS: Our programmatic approach to thymectomy through a sternotomy has shown minimal morbidity and mortality. It is beneficial to myasthenics at both ends of the age and severity spectrum.

Adult↗
PubMed1996

Management and outcome of chronic atherosclerotic infrarenal aortic occlusion.

PURPOSE: To evaluate the management and outcome of chronic atherosclerotic infrarenal aortic occlusion (IRAO), a review of 48 patients who were treated for angiographically documented IRAO between January 1980 and December 1994 was undertaken. Mean follow-up was 45 months. Mean age was 57 years (range, 33 to 88 years). Forty-seven patients were heavy smokers. Symptoms included claudication in 81%, rest pain in 25%, and tissue loss in 15%. Impotence was documented in 73% of men. Associated arterial disease included inferior mesenteric artery occlusion in 31 patients, renal artery stenosis or occlusion in 12, superior mesenteric artery stenosis in two, and celiac artery stenosis in one. METHODS: Forty inflow procedures were performed, including 17 thoracobifemoral bypass (TBF) procedures, 15 aortobifemoral/iliac bypass (ABFI) procedures, and eight axillobifemoral bypass (AXBF) procedures. Eight patients were managed without surgery. The thoracic aorta was chosen as the inflow source in 17 patients because of previous abdominal aortic surgery in eight, poor status of the abdominal aorta in eight, and horseshoe kidney in one. RESULTS: The overall operative mortality rate was 5%, and the perioperative morbidity rate was 18%. There was no statistical difference in perioperative mortality and morbidity rates among the operative groups. The five-year survival rate (life-table) for all IRAO patients was 67%. TBF and ABFI revascularization procedures yielded 5-year patency rates of 71% and 79%, respectively (p < 0.05). All eight patients who underwent AXBF died or had occluded grafts at 3 years after surgery. Two-year patency rates (life-table) for TBF, ABFI, and AXBF were 92%, 92%, and 44%, respectively. The AXBF patency rate was significantly inferior to those of TBF and ABFI (p < 0.05). Changes in ankle-brachial indexes after TBF or ABFI were similar, but were significantly greater than changes after AXBF (p < 0.05). Three patients in the nonoperative group died, and two underwent major amputation. Acute renal failure did not occur in our study population. Follow-up creatinine levels > 2.0 mg/dl were documented in three operative patients and in one nonoperative patient, and none required dialysis. CONCLUSIONS: In patients who have IRAO, aorta-based inflow procedures are superior to AXBF both in hemodynamic outcome and in patency rates. Treatment of IRAO with TBF or ABFI yields similar long-term results; the descending thoracic aorta represents an excellent inflow alternative to the abdominal aorta. Clinically significant renal impairment is rarely associated with IRAO. Nonoperative management of IRAO is associated with an increased mortality rate and a high rate of limb loss.

Adult↗
PubMed1995

Physiologic variations in lower extremity venous valvular function.

We conducted this study to investigate the physiologic variations in venous valvular function and calf muscle pump function that occur in normal limbs after prolonged stationary standing. Twenty-two limbs from 11 healthy volunteers were studied after a brief period of activity and after 4 to 6 hours of stationary standing. Vein diameter, peak reflux flow velocity (PRFV), and valve closure time (VCT) were measured with duplex scanning in the standing position in the common femoral vein (CFV), superficial femoral vein (SFV), popliteal vein (POP), proximal greater saphenous vein (GSV), and greater saphenous vein at the knee (kGSV). Pneumatic rapid inflation-deflation cuffs were used to elicit reflux. Vein cross-sectional area (VA) and peak reflux volume (PRVol) were calculated. Venous volume (VV), venous filling index (VFI), ejection fraction (EF), residual volume fraction (RVF), and outflow fraction (OF) were measured with air plethysmography in all limbs. After stationary standing, there was no significant change or trend toward an increase in diameter or VA in any of the deep veins and there was no change in the PRFV or VCT. In the proximal GSV there was a significant increase in diameter (p = 0.0001) and VCT (p = 0.048) without a change in PRFV. No significant changes were noted in the kGSV. In the GSV the PRFV was significantly lower (p < 0.05) and the VCT significantly shorter (p < 0.05) compared with the SFV and POP but values were no different from those in the CFV. The PRFV was significantly higher in the SFV (p < 0.0001) and the POP (p < 0.002) compared with that in the CFV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Extrathoracic reconstruction of arterial occlusive disease involving the supraaortic trunks.

PURPOSE: The purpose of this study was to review the various extrathoracic reconstruction options in patients with occlusive disease of the supraaortic trunks and to define the efficacy of these procedures in maintaining graft patency and relieving symptoms. METHODS: Forty-four consecutive patients underwent 47 extrathoracic bypass procedures of the supraaortic trunks for correction of symptomatic subclavian (SCA), common carotid (CCA) or innominate (INA) artery occlusive disease between July 1975 and May 1994. SCA stenosis (n = 27) was associated with upper extremity claudication (55%), vertebrobasilar insufficiency (15%), or both (30%). CCA stenosis (n = 14) was accompanied by hemispheric symptoms in 86% and global ischemia in 14%, whereas INA stenosis (n = 3) was associated with transient ischemic attacks (67%) and right arm ischemia (33%). RESULTS: SCA revascularization included carotid-subclavian or carotid-axillary bypass (n = 19), axilloaxillary bypass (n = 8), and subclavian-carotid transposition (n = 3). CCA reconstructions included subclavian-carotid (SC) bypass (n = 13) and carotid-carotid bypass (n = 1). INA procedures included three axilloaxillary bypasses. Six patients had an associated carotid endarterectomy, and three underwent concomitant vertebral artery transpositions. Intraluminal shunts were not routinely used. Vein was used as a conduit in five procedures, and a prosthetic graft (23 Dacron, 16 polytetrafluoroethlyene) was used in the remainder. The average postoperative intensive care unit and hospital and hospital stay were 1 and 5 days, respectively. Follow-up was available in 43 of 44 patients (mean = 26.2 months). The perioperative mortality rate was 2.2% (one axilloaxillary). There were five graft occlusions in procedures involving the axillary artery (3 of 11 axilloaxillary, 2 of 7 carotid-axillary) as compared with one of 29 thromboses when the operation was confined to the supraclavicular fossa (p < 0.05) Relief of symptoms was achieved in all patients with patent grafts. There were no perioperative strokes in the series. Other complications included one brachial plexus neuropraxia (axilloaxillary) and four patients with phrenic nerve neuropraxia. CONCLUSION: Extrathoracic revascularization of the supraaortic trunks is well tolerated and durable when operations are confined to the supraclavicular fossa and do not involve the axillary artery.

Adult↗
PubMed1995

An aortic aneurysm model for the evaluation of endovascular exclusion prostheses.

PURPOSE: The purpose of this study was to develop an aortic aneurysm (AA) model with a predictable tendency for rupture for the evaluation of the efficacy of endovascular prostheses in preventing rupture and their long-term outcome after implantation. METHODS: An infrarenal AA measuring two to three times the diameter of the proximal aorta was created in 18 dogs with a full-thickness patch of jejunum. Seven dogs were allowed to survive without aneurysm exclusion. In 11 dogs the aneurysm was immediately excluded with a stented 8 mm Dacron graft mounted in a 14F delivery system introduced through the femoral artery with aortographic guidance. The pressure differential between the aorta and the excluded aneurysm was measured, and angiography, necropsy, and histologic examination were performed at 3- and 6-month survival. RESULTS: All animals survived aneurysm implantation. Without aneurysm exclusion, six dogs died of rupture within 1 to 6 days of surgery. In three dogs the exclusion failed because of graft-to-aorta size mismatch or misplacement demonstrated on angiography and by a low pressure differential between the aorta and the aneurysm (< 5 mm Hg); all three dogs died of rupture within 4 days. In eight dogs the aneurysm was successfully excluded on the basis of angiography results, with a mean aorta-to-aneurysm pressure differential of 51 mm Hg. Two dogs were killed at 1 and 6 days after surgery because of paraplegia produced by graft thrombosis because of kinking but without evidence of aneurysm rupture. Six dogs survived on a long-term basis, and angiography and necropsy performed at 3 and 6 months revealed patent grafts without migration, reduction in aneurysm size, no flow in the excluded lumbar arteries in five of six animals, and complete incorporation of Dacron graft and stents. No evidence of graft infection was found in any animal. The survival rate was significantly better (p < 0.023) in dogs with successfully excluded aneurysms (n = 6) compared with that in dogs without exclusion or with failed aneurysm exclusion (n = 7). CONCLUSION: This aneurysm model demonstrates that without effective aneurysm exclusion all animals die of rupture and that successfully placed endovascular prostheses can prevent AA rupture with long-term graft patency and stability. Endovascular aortic Dacron grafts in dogs undergo complete incorporation at 3 months from implantation. This aneurysm model is useful for the evaluation of endovascular devices designed for the treatment of AAs.

Animals↗
PubMed1995

Transbrachial endovascular exclusion of an axillary artery pseudoaneurysm with PTFE-covered stents.

PURPOSE: Endovascular exclusion of arterial injuries associated with arteriovenous fistulas and pseudoaneurysms has only recently been described using various stent-graft prostheses. This report details a transbrachial technique used to exclude an axillary artery pseudoaneurysm developing at the axillary anastomosis of an axillofemoral graft. METHODS AND RESULTS: Thin-walled polytetrafluoroethylene was expanded with an angioplasty balloon catheter and used to cover standard Palmaz stents. Two covered stents were delivered under fluoroscopic guidance via open brachial artery access to the site, resulting in complete exclusion of the pseudoaneurysm. Follow-up duplex scanning confirmed aneurysm exclusion 3 months postprocedure. CONCLUSIONS: This technique can be applied in arteries of different sizes and lengths, using currently available materials. However, the long-term behavior of these devices in the arterial tree must be determined before their widespread use can be recommended for most indications.

Aged↗
PubMed1994

Proximal venous outflow obstruction in patients with upper extremity arteriovenous dialysis access.

To evaluate the impact of central venous obstruction on upper extremity hemodialysis access failure, we retrospectively analyzed our recent experience in managing this problem. We reviewed 158 upper extremity hemodialysis access procedures performed in 122 patients during a 1-year period. Fourteen (11.5%) patients had central vein obstruction as the cause of severe arm swelling, graft thrombosis, or graft malfunction. All 14 patients had had bilateral temporary subclavian vein dialysis catheters and failed upper extremity arteriovenous access. Seventeen lesions were treated in 14 patients including eight subclavian vein occlusions, six subclavian vein stenoses, two internal jugular vein stenoses, and one superior vena cava stenosis. Twenty-one procedures were performed including 17 percutaneous transluminal balloon angioplasties (PTAs) with stent placement in 13, two axillary to innominate vein bypasses, and two axillary to internal jugular vein bypasses. All patients had resolution of symptoms. Thirteen (76%) PTAs were initially successful but in four (24%) cases it was impossible to recanalize the vein. Eight (47%) PTAs provided functional hemodialysis access for 2 to 9 months, two (12%) restenosed at 3 and 10 months and were successfully redilated, two occluded at 2 and 4 months and were unable to be recanalized, and one failed immediately after a successful PTA. Four PTA failures were followed by venous bypass, which remained patent and provided functional access 7 to 13 months after surgery. Of nine stenotic venous lesions six (67%) were successfully dilated without restenosis, whereas of eight occluded veins only two (25%) were successfully treated without recurrence. Temporary central hemodialysis catheters produce a significant number of symptomatic central vein obstructions in patients with upper extremity arteriovenous access.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1994

Use of the descending thoracic aorta as an inflow source in aortoiliac reconstruction: indications and long-term results.

Bypass grafting from the descending thoracic aorta to the iliac or femoral artery is an underutilized procedure; fewer than 200 cases were reported in the past 30 years. Over the last decade we performed 32 bypasses to the femoral iliac or popliteal arteries using the descending thoracic aorta as the inflow source. In 19 (59%) patients the procedure was a primary aortic reconstruction, whereas in 13 (41%) it was secondary. The 30-day in-hospital mortality rate was 6.2%. Primary graft patency was 86% (+/- 7.8) at 2 years. To obtain a meaningful long-term patency analysis, we combined our experience with that reported in the literature during the same period. Follow-up data were available in 146 patients in whom the mean follow-up time ranged from 15 to 53 months. The operation was a secondary aortic reconstruction in 84 (58%) patients and was a primary procedure in 62 (42%). Reasons for the selection of the descending thoracic aorta as the inflow source included previous abdominal aortic graft failure in 56 (38%) patients, abdominal aortic graft infection in 26 (18%), unfavorable abdominal conditions in 30 (21%), and miscellaneous causes in 34 (23%). The 30-day in-hospital mortality rate for the collective experience was 5.5%. Life-table analysis of the collective primary graft patency rate was 88.3% (+/- 2.9) at 1 year, 81% (+/- 4.3) at 3 years, and 72.7% (+/- 8.5) at 6 years. Secondary graft patency for the collective experience was 93.1% (+/- 2.3) at 1 year, 88.2% (+/- 3.7) at 3 years, 82.7% (+/- 7.3) at 6 years, and 82.7% (+/- 10) at 8 years. Patient survival was 67.5% (+/- 6.9) at 5 years and 55.4% (+/- 9.9) at 7 years. These data suggest that bypass from the descending thoracic aorta to the iliac or femoral arteries offers low mortality and excellent durability and should be considered as the procedure of choice for secondary or extra-anatomic aortoiliac reconstruction.

Aged↗
PubMed1994

Management of failed and infected axillofemoral grafts.

PURPOSE: The purpose of this study was to review the treatment of patients with failed or infected axillofemoral bypass grafts and to determine the efficacy of remedial procedures in maintaining graft patency and limb preservation. METHODS: Thirty-four patients with 37 failed or infected axillofemoral grafts were retrospectively reviewed. In nine cases there was no attempt at revascularization, and in the remaining 28 cases, a total of 52 remedial procedures was performed. Nine were performed in patients with graft infection and 43 in patients with graft thrombosis. In patients with axillofemoral graft failure, 21 thrombectomies, 13 graft revisions, and 9 secondary reconstructions were performed. Eighty-eight percent of patients were monitored at least 2 years or until graft failure. RESULTS: Eight of nine patients receiving no remedial procedure required major amputation. The limb salvage rate was 64% +/- 11% at 30 months in the 25 patients undergoing remedial procedures. Twenty-eight percent of failed axillofemoral grafts remained patent at 2 years after initial failure with single or multiple thrombectomies or revisions. Life-table primary patency after secondary reconstructions (81% +/- 10.9% at 24 months) was significantly better than after thrombectomy alone (10% +/- 4.2% at 24 months) or graft revision (16% +/- 10.6% at 24 months) by log-rank test (p < 0.001 and p < 0.005, respectively). Patients undergoing reconstruction with descending thoracic aorta to femoral artery bypass had an 89% +/- 11% patency rate at 24 months. Graft infection resulted in a perioperative mortality rate of 22% and amputation in 57% of survivors. CONCLUSION: Axillofemoral graft failure most often results in limb loss without remedial procedures. Thrombectomy and revision procedures had poor long-term patency rates and salvaged only a minority of grafts despite multiple procedures. Reconstruction by use of an alternate source of inflow such as the descending thoracic aorta resulted in better long-term patency rates in patients well enough to tolerate a major reoperative procedure.

Amputation, Surgical↗
PubMed1993

Progression of occlusive disease following femorofemoral crossover bypass graft.

Progression of distal disease is considered the most common cause of femorofemoral artery crossover bypass graft (FFBPG) failure. Twenty-seven patients with patient grafts (mean 53 months) were evaluated with segmental Doppler and duplex scan arterial studies for evidence of disease progression. In the early postoperative period (compared with preoperative levels), 26 patients (95.3%) showed a significant improvement (> 0.1) in the recipient limb ankle-brachial index (ABI) (mean increase of 0.38; SD = 0.24) and/or ankle spectral arterial waveform. However, there was a statistically significant decrease (p = 0.0001) in the donor limb ABI, and 12 patients (44.4%) had a > 0.1 deterioration. On long-term follow-up (compared with preoperative levels) this difference was no longer significant (p = 0.49); only seven donor limbs remained with a > 0.1 decrease in ABI. The recipient limbs maintained a significant improvement (> 0.1) in the ABI compared to preoperative levels (p < 0.0001; mean of 0.39; SD = 0.16) except for three limbs that had decreased by 0.1. However, eight patients (29.6%) developed an increase in their donor common femoral artery acceleration time > 133 msec and/or increased blood flow velocity without a simultaneous significant decrease in their recipient limb ABI. In the latter group the preoperative donor limb common femoral artery acceleration time and ABI and the immediate postoperative change in donor limb ABI were not significantly different (p > 0.05) than in the remaining patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Arterial Occlusive Diseases↗
PubMed1993

Femorofemoral bypass graft: analysis of patency and factors influencing long-term outcome.

PURPOSE: To evaluate the results of femorofemoral bypass graft (FFBPG), we analyzed 110 consecutive FFBPGs performed at our institution during an 11-year period. METHODS: In 62 (56%) patients the indication for surgery was claudication and in 48 (44%) patients rest pain or tissue loss. In 42 patients the superficial femoral artery (SFA) was occluded. A preoperative percutaneous transluminal balloon angioplasty (PTA) was performed in 24 (22%) patients to correct a significant donor iliac artery stenosis. In 48 (44%) patients a total of 54 arterial procedures were performed simultaneously with FFBPG. RESULTS: After surgery 75 (68%) patients were moderately or markedly improved, whereas 20 (18%) were minimally improved, unchanged, or worse, including 7 (6%) with hemodynamic failures. The in-hospital mortality rate was 4.5%. Actuarial patient survival rate was 70% +/- 8.6% at 6 years. The actuarial primary graft patency rate was 83% +/- 4.2% at 1 year, 71% +/- 6.9% at 3 years, 60% +/- 8.3% at 5 years, and 51% +/- 9.6% at 6 years. Age, sex, and race of the patient did not influence graft patency. Grafts placed for limb-threatening ischemia or in patients with SFA occlusion had a similar patency rate compared with those placed for claudication or in patients with patient SFA. The overall limb preservation rate was 83% +/- 7.3% at 5 years but was only 64% for patients who underwent operation for limb-threatening ischemia. CONCLUSIONS: In conclusion, FFBPG offers moderately low long-term patency in a population with limited survival. Outflow procedures performed concomitantly with FFBPG seemed to compensate for the negative impact on graft patency rate of ipsilateral SFA occlusion and limb-threatening ischemia. Limb-threatening ischemia, however, carried a significantly higher (p < 0.05) amputation rate. The influence of preoperative donor iliac artery percutaneous transluminal balloon angioplasty on FFBPG patency remains unclear.

Adolescent↗
PubMed1992

Flow cytometric analysis of organ preservation-induced endothelial cell membrane damage.

Organ preservation for transplantation is associated with endothelial cell damage. This vascular injury results in increased capillary permeability, graft edema, and early graft dysfunction. This damage may be the limiting factor in preservation of these organs. This study uses flow cytometric assessment of membrane integrity to examine the effects of various organ preservation solutions on human umbilical vein endothelial cell cultures. Confluent plates of human umbilical vein endothelial cells were incubated at 4 degrees C for 24, 48, and 72 hours in commonly used preservation solutions. After cold incubation, the cells were harvested and stained with propridium iodide and fluorescein diacetate. Cells were examined using a flow cytometer for membrane integrity and cytosolic activity. When examined after 24, 48, and 72 hours, cells stored at 4 degrees C in a 5% polyethylene glycol salt solution were significantly less damaged than those stored in any other solution (p less than 0.05). After 48 and 72 hours at 4 degrees C, cells stored in ViaSpan were significantly more intact than cells stored in EuroCollins and 0.9% saline solution (p less than 0.05). This study demonstrates that endothelial cell damage occurs during cold storage and that a polyethylene glycol-based solution showed superior cellular preservation.

Adenosine↗
PubMed1992

Isolated lung transplantation for end-stage lung disease: a viable therapy.

Since January 1990, we have performed 29 isolated lung transplantations in 28 patients with end-stage lung disease (12 single, 16 bilateral). Recipient diagnoses were: cystic fibrosis (11), chronic obstructive pulmonary disease (6), pulmonary fibrosis (6), eosinophilic granulomatosis (1), postinfectious lung disease (1), adult respiratory distress syndrome (1), and primary pulmonary hypertension (2). There have been four deaths, two in patients with pulmonary fibrosis and two in patients with primary pulmonary hypertension. Four patients have undergone transplantation while on ventilatory support for respiratory failure (2 with cystic fibrosis, 1 having redo lung transplantation with cystic fibrosis, and 1 with adult respiratory distress syndrome); all of these have survived. Six patients required cardiopulmonary bypass, which was associated with increased transfusion requirement. All patients 2 months after discharge have returned to an active life-style, except for 2 patients who currently await retransplantation. Preoperative pulmonary rehabilitation has resulted in significant improvement in exercise performance in all patients. Immunosuppression consists of cyclosporine, azathioprine, and antilymphoblast globulin (University of Minnesota), withholding systemic steroids in the early postoperative period. We have employed bronchial omentopexy in all but four transplants; there has been one partial bronchial dehiscence, two instances of bronchomalacia requiring internal stenting, and one airway stenosis. Cytomegalovirus disease has been seen frequently (15 cases), but has responded well to treatment with ganciclovir. Other complication shave included one drug-related prolonged postoperative ventilation, thrombosis of a left lung after bilateral lung transplantation requiring retransplantation, five episodes of unilateral phrenic nerve palsy after bilateral lung transplantation (4 resolved), and the requirement of massive transfusion (greater than 10 units) in 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Descending thoracic aorta-to-iliofemoral artery bypass as an alternative to aortoiliac reconstruction.

During the last 3 decades subcutaneous extraanatomic bypass, despite its limited durability, has been the favored alternative to infrarenal aortofemoral bypass. Meanwhile, the descending thoracic aorta has been scarcely used as an inflow source for aortoiliac reconstruction. Over the past 8 years we performed 16 bypasses from the descending thoracic aorta to the iliofemoral vessels for occlusive disease. Our experience combined with that found in the English-language literature totaled 141 patients. In 79 patients (56%) the indication for surgery was failure or infection of an abdominal aortofemoral graft. Previous abdominal operations, sepsis, radiation therapy, the presence of abdominal stomas, or an unsuitable infrarenal aorta were the indications in the remaining cases. The combined operative mortality rate was 6.4%. The life-table primary graft patency was 98% at 1 year, 88% at 2 years, and 70.4% at 5 years. Bypass from the descending thoracic aorta to the iliofemoral artery uses an inflow source superior to other extraanatomic reconstructions, does not require aortic cross-clamping, avoids the abdominal cavity, and places the graft remote to the skin and intestine. The operative mortality and patency rates compare favorably to those of other extraanatomic or remedial aortic reconstructions. Descending thoracic aorta to iliofemoral artery bypass is a superb alternative to abdominal aortofemoral bypass, carries a low mortality rate, has an excellent short-term patency, and features unique characteristics for long-term durability.

Adult↗
PubMed1992

Single lung transplantation for eosinophilic granulomatosis.

A 26-year-old woman with end-stage lung disease due to eosinophilic granulomatosis had single right lung transplantation with an excellent function result that persists beyond 9 months of follow-up. Single lung transplantation offers excellent palliation to selected patients with end-stage lung disease.

Adult↗
PubMed1992

Endothelial cell preservation using organ storage solutions.

The development of organ preservation solutions has been primarily accomplished in whole organ animal models. This study examines the toxicity of commonly used organ preservation solutions on endothelial cells in vitro. Primary human umbilical-vein endothelial cell cultures were incubated at 4 degrees C in solutions of 0.9% saline (NS), EuroCollins, ViaSpan (Belzer UW) (VIA), or Hank's balanced salts with 5% polyethylene glycol (PEG). Endothelial cell viability was ascertained by colormetric measurement of mitochondrial reduction of 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) to purple 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan. After exposure to hypothermic storage, cells were incubated at 37 degrees C in media with MTT, and the amount of reduced formazan present was quantified using a micro-ELISA spectrophotometer. Higher absorbance values were indicative of better cellular preservation. Cells stored in PEG displayed the highest viability at all time periods. ViaSpan provided better cellular protection than EC at longer storage intervals. This model allows for rapid assessment of preservation-induced endothelial cell injury and may aid development of improved storage techniques.

Absorption↗
PubMed1992

Improvement of endothelial cell viability at 4 degrees C by addition of lazaroid U74500A to preservation solutions.

Lazaroids are potent inhibitors of lipid peroxidation. Endothelial cell damage has been shown to occur during cold storage preservation of lung and liver. This study examines the effects on endothelial cell viability of the addition of four lazaroids, U74006F, U78518F, U74500A, or U75412E to preservation solutions. Human umbilical vein endothelial cell cultures were stored at 4 degrees C for 48 and 96 hr in EuroCollins or 5% polyethylene glycol in buffered saline (PEG). U78518F, U74500A, U74006F, U75412E, or dexamethasone (each 50 microM) was added to EC (n = 32) or PEG (n = 32) and compared with control solutions of EC or PEG alone. Endothelial cell viability was determined by measuring cellular reduction of 3-[4,5-dimethylthiazol-2-yl]-2,3-diphenyltetrazolium bromide to a purple formazan dye. The reduction occurs only in viable cells and requires mitochondrial dehydrogenase activity. Results were quantified by measuring dye absorbance (Ab) with a micro-ELISA spectrophotometer. Absorbance values were compared by ANOVA and reported as mean values +/- standard deviation. Addition of U74500A to EC (Ab = 0.474 +/- 0.055) and PEG (Ab = 0.462 +/- .005) improved viability at 48 hr when compared with EC (Ab = 0.289 +/- 0.069) and PEG (Ab = 0.287 +/- 0.052) alone (P less than 0.05). At 96 hr, addition of U74500A resulted in improved viability in both EC (Ab = 0.377 +/- 0.068) and PEG (Ab = 0.195 +/- 0.09) or PEG alone (Ab = 0.212 +/- 0.1) (P less than 0.05). Other lazaroids tested were also effective in improving cellular viability, but to a lesser degree than U74500A. This study demonstrates that the addition of lazaroids to organ preservation solutions improves endothelial cell viability.

Absorption↗